'83 Evinrude XP 150 used to turn over and run but tried for the first time in 8 months today and it won’t budge. I even put a ratchet on it and still nothing. Dont want to force it too much in fear of bending con rod or something. I sprayed some liquid wrench in the cylinders and will let that sit for a while. Any ideas would be great, thank you
Mike
12’ Jon boat twin 300 Verados
ok, so no knew ideas on how to break free an engine…maybe apply heat? Although not sure how Id do that evenly on 6 cyl. What lube is best to let sit in cyl’s for a couple days to eat up any rust etc… on rings/cyl walls? Break free? Liquid wrench? I was going to tilt engine all the way up, remove plugs again, spray a bunch of something in there and let it sit. If anyone has done anything that has been successful let me know. Thanks
Mike
12’ Jon boat twin 300 Verados
Ok so a bump and update. I’ve sprayed a little break free in the cylinders and it has been sitting tilted full up with that break free for a couple days now. I have added some every now and then also. It is still tight as a drum. I sincerely doubt it is the pistons or a piston (rings or whatever) that are THAT stuck. So, I thought Id just remove the fly wheel and see if there was serious rust on top. I cant even get the fly wheel off with a puller. What gives? Besides NOT my engine that is. Is there a secret way to remove fly wheel it should just be that center nut right? Any help and/or suggestions would be greatly appreciated. I hope everyone is having a great Labor Day weekend
Mike
12’ Jon boat twin 300 Verados
Foot could be locked up. Even in neutral the main shaft has to turn.
If the foot was locked up, would the prop turn in neutral and not turn in gear (perspectively fwd and reverse)? The L/U seems to be fine. Not sure what is keeping the power head from turning. Thank you for the idea Waterbreaker…I didnt think anyone could see the post until I saw it
Mike
12’ Jon boat twin 300 Verados
Depends on where the lower unit is locked up. If its in the drive shaft(between the engine and what is basicly the transmission) the prop would turn freely in neutral.
remove the lower unit from the motor and try again. or take the plug out of the bottom of the lower unit and smell the oil and also look to see what color the oil is. another trick to getting the flywheel off… with the puller on the flywheel get the puller tight as if you were trying to remove the fly wheel and give the top of the puller bolt a medium strength solid hit with a hammer. has worked for me in the past
197 poineer F150
31 yellowfin twin 275
motor is completely frozen…like it might as well be a solid piece of metal. Looking for a Evinrude/Johnson 150 on a serious budget. I have all controls and tilt/trim, just need engine or power head. THanks everyone for the ideas.
Mike
12’ Jon boat twin 300 Verados
Did you pull the plugs to try and turn it w/out any compression against your effort to rotate it??
yes sir, plugs were out everytime I tried to turn it. I am currently shopping for a good powerhead Erude, Johnson, OMC. Anyone know of where I can get one for cheap and I dont mean cheap…I mean C-H-E-A-P…I guess if anyone knew, they would not have any motors left
Mike
12’ Jon boat twin 300 Verados
pull the heads
see if one cylinder is rusted
sometimes a leaking headgasket will let water in a cylinder causing the rings to stick to the cylinder wall.
with a block of wood, you can smack teh top of the piston, and possibly break it free. you could get lucky and run it for a while and maybe the rings free up, or you may have bad compression on 1 cylinder. or you may break the piston, but no matter what, you arent any worse than you are now, and it may actually work.
quote:Excellent approach sir. I actually started to pull the heads and will be able to do all you suggested today. I didn't think of a head gasket leaking. Thank you very much. And that is exactly right, it might work good for me for a little while. It is just a bass boat so the worste case is It'll blow in the middle of a lake :)
chris V Senior Member6135 Posts
Posted - 09/09/2010 : 11:02:11 AMpull the heads
see if one cylinder is rusted
sometimes a leaking headgasket will let water in a cylinder causing the rings to stick to the cylinder wall.
with a block of wood, you can smack teh top of the piston, and possibly break it free. you could get lucky and run it for a while and maybe the rings free up, or you may have bad compression on 1 cylinder. or you may break the piston, but no matter what, you arent any worse than you are now, and it may actually work.
Mike
12’ Jon boat twin 300 Verados
Ok Chris so I should have thought about that earlier (a leaking head gasket). I wish I would have taken pictures but I was on a role, got the heads off and WOW. Two of the cylinders looked like they were coated in barnacles is was HORRIBLE!!! I was very nervous to get rid of that rust too because I was afraid of pitting in the cyl walls. Anyways, used scotch bright and liquid wrench and eventually got some movement only having to tap the pistons lightly and just a few times. I got all 6 cylinder walls shiny, unscored (they were not pitted thank God, literally) and the pistons were all carboned up so I scotch brighted those. The engine sat with OLD gas in the cyls and out in the weather for 9 months over a deployment. I can now turn the engine very freely with the fly wheel. Just have to reassemble and fire it up. Thank you all for the suggestions and especially Chris V for jogging my brain. I think that engine will work good for a little while at least. For those of you that get a seized engine there is always hope! 
Mike
12’ Jon boat twin 300 Verados
Roger that, will do in the AM and report compression. What numbers would be acceptable? I know it is almost more important that they are even but I also know that 50psi isnt good. The Merc I used to have had 100+ - 3 psi on all 6 just not sure about John-Rude-OMC. Thank you
Mike
12’ Jon boat twin 300 Verados
Ok, got new headgaskets on, torqued down appropriately etc… Now, the compression SUCKS! My first thought is this: if the engine was frozen THAT solidly, I know a ring could have bent or broken HOWEVER, is it possible the rings are stuck around pistons and are allowing this lousy compression? Will “Ring Free” sprayed down carb or added to fuel help or do I just need to tear engine down and put new rings on it? Thanks again for the help, this is an awesome website
Mike
12’ Jon boat twin 300 Verados
the compression should be around 100
I would suggest trying to run it for a while, if it will run
yes, the rings could easily be stuck
ring free probably isnt going to help much, its made to remove carbon, not rust.
just run and see what happens
if the compression doesnt come back to at least 80 on all cylinders, you are going to have to break it down, have the block honed, and replace all the rings
Roger, thanks Chris
Mike
12’ Jon boat twin 300 Verados